Lactose
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
| Lactose | |
|---|---|
| |
| Identifiers | |
| CAS number | |
| PubChem | |
| MeSH | |
| Properties | |
| Molecular formula | C12H22O11 |
| Molar mass | 342.296 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references | |
Lactose is a disaccharide that consists of β-D-galactose and β-D-glucose molecules bonded through a β1-4 glycosidic linkage. Lactose makes up around 2-8% of the solids in milk. The name comes from the Latin word for milk, plus the -ose ending used to name sugars.
Digestion of lactose
Infant mammals are fed on milk by their mothers. To digest it an enzyme called lactase (β1-4 disaccharidase) is secreted by the intestinal villi, and this enzyme cleaves the molecule into its two subunits glucose and galactose for absorption.
Since lactose occurs mostly in milk, in most species the production of lactase gradually ceases with maturity, and they are then unable to metabolise lactose. This loss of lactase on maturation is also the default pattern in most adult humans.[1] However, many people with ancestry in Europe, the Middle East, India, or parts of East Africa, maintain lactase production into adulthood. In many of these cultures other mammals such as cattle, goats, and sheep are milked for food.
This fact may cast doubt on some arguments by proponents of the Paleolithic diet,[citation needed] who argue that human metabolic needs have not changed since the last ice age. The process of retaining infant characteristics into adulthood is one of the simplest routes of adaptation, and is known as neoteny.
Solubility
8 g lactose per 10 g [2]
Lactose has a solubility of 1 in 4.63 measured %w/v. This translates to 0.216g of lactose dissolving readily in 1mL of water.
The solubility of lactose in water is 18.9049 g at 25 °C, 25.1484 g at 40 °C and 37.2149 g at 60 °C per 100 g solution. Its solubility in ethanol is 0.0111 g at 40 °C and 0.0270 g at 60 °C per 100 g solution. [3]
See Also
External links
- Study Detects Recent Instance of Human Evolution (Finding that lactose tolerance is a recent change)
- Lactose Intolerence (click on the link for more information)
ca:Lactosa cs:Laktóza da:Laktose de:Milchzuckereo:Laktozois:Laktósi it:Lattosio he:לקטוז lt:Laktozė mk:Лактоза nl:Lactoseno:Laktosesimple:Lactose sl:Laktoza sr:Лактоза fi:Laktoosi sv:Laktosuk:Лактоза
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
